For global automakers, the world is flat û except in Asia

When it comes to car sales, Asia, with its booming Chinese and Indian economies, is the exception to the global rule.

A tour of today's global auto market is hardly the stuff of a sunny afternoon cruise with the top down. Instead, carmakers find themselves forced to contend with a host of hazardous road conditions, ranging from uncertain economic prospects in major markets to fuel prices that look like they want to go only upward. And to complete this risky picture, throw in changing demographic patterns, the volume of cars already on the roads, how long vehicles last, and, of course,...